#ifndef __M_FMT_H__
#define __M_FMT_H__
#include <ctime>
#include <sstream>
#include "message.hpp"
#include "level.hpp"
#include <vector>
#include <assert.h>
namespace log
{
    // 抽象格式化子项基类
    class FormatItem
    {
    public:
        using ptr = std::shared_ptr<FormatItem>;
        virtual void format(std::ostream &out, const LogMsg &msg) = 0;
    };
    // 派生格式化子项子类---消息，等级，时间，文件名，行号，线程ID，日志器名称，制表符，换行，其他
    class MsgFormatItem : public FormatItem
    {
    public:
        MsgFormatItem(const std::string &str ="") {}

        void format(std::ostream &out, const LogMsg &msg)
        {
            out << msg._payload;
        }
    };
    class LevelFormatItem : public FormatItem
    {
    public:
        LevelFormatItem(const std::string &str = "") {}

        void format(std::ostream &out, const LogMsg &msg)
        {
            out << log::LogLevel::toString(msg._level);
        }
    };
    class TimeFormatItem : public FormatItem
    {
    public:
        TimeFormatItem(const std::string &fmt = "%H:%M:%S")
            : _time_fmt(fmt)
        {
        }
        void format(std::ostream &out, const LogMsg &msg)
        {
            struct tm t;
            localtime_r(&msg._ctime, &t);
            char tmp[32] = {0};
            strftime(tmp, 31, _time_fmt.c_str(), &t);
            out << tmp;
        }

    private:
        std::string _time_fmt; //%H:%M:%S
    };
    class FileFormatItem : public FormatItem
    {
    public:
        FileFormatItem(const std::string &str = "") {}

        void format(std::ostream &out, const LogMsg &msg)
        {
            out << msg._file;
        }
    };
    class LineFormatItem : public FormatItem
    {
    public:
        LineFormatItem(const std::string &str = "") {}

        void format(std::ostream &out, const LogMsg &msg)
        {
            out << msg._line;
        }
    };
    class ThreadFormatItem : public FormatItem
    {
    public:
        ThreadFormatItem(const std::string &str = "") {}
        void format(std::ostream &out, const LogMsg &msg)
        {
            out << msg._tid;
        }
    };
    class LoggerFormatItem : public FormatItem
    {
    public:
        LoggerFormatItem(const std::string &str = "") {}
        void format(std::ostream &out, const LogMsg &msg)
        {
            out << msg._logger;
        }
    };
    class TabFormatItem : public FormatItem
    {
    public:
        TabFormatItem(const std::string &str = "") {}
        void format(std::ostream &out, const LogMsg &msg)
        {
            out << "\t";
        }
    };
    class NLineFormatItem : public FormatItem
    {
    public:
        NLineFormatItem(const std::string &str = "") {}
        void format(std::ostream &out, const LogMsg &msg)
        {
            out << "\n";
        }
    };
    class OtherFormatItem : public FormatItem
    {
    public:
        OtherFormatItem(const std::string &str = "")
            : _str(str)
        {
        }
        void format(std::ostream &out, const LogMsg &msg)
        {
            out << _str;
        }

    private:
        std::string _str;
    };
    class Formatter
    {
    public:
        //  %d ⽇期
        //  %T 缩进
        //  %t 线程id
        //  %p ⽇志级别
        //  %c ⽇志器名称
        //  %f ⽂件名
        //  %l ⾏号
        //  %m ⽇志消息
        //  %n 换⾏
        using ptr=std::shared_ptr<Formatter>;
        Formatter(const std::string &pattern = "[%d{%H:%M:%S}][%t][%c][%f:%l][%p]%T%m%n")
            : _pattern(pattern)
        {
            assert(parsePattern()); // 如果传入的字符串解析有误，则字符串有误，则无需往后走
        }
        // 对msg进行格式化
        void format(std::ostream &out, const LogMsg &msg)
        {
            for (auto &item : _items)
            {
                item->format(out, msg); // 这个format不是递归，而是调用上面继承了抽象类的format
            }
        }
        std::string format(const LogMsg &msg)
        {
            std::stringstream ss;
            format(ss, msg);
            return ss.str();
        }
        // 对格式化规则的字符串进行解析
    private:
        bool parsePattern()
        {
            // 1.对格式化规则字符串进行解析
            // abcde[%d{%H:%M:%S}][%p]%T%m%n
            std::vector<std::pair<std::string, std::string>> fmt_order;
            size_t pos = 0;
            std::string key, val;
            while (pos < _pattern.size())
            {
                if (_pattern[pos] != '%')
                {
                    val.push_back(_pattern[pos++]);
                    continue;
                }
                if (pos + 1 < _pattern.size() && _pattern[pos + 1] == '%')
                {
                    // 双%，处理成一个原始%字符
                    val.push_back('%');
                    pos += 2;
                    continue;
                }
                if (val.empty() == false)
                {
                    fmt_order.push_back(std::make_pair("", val));
                    val.clear();
                }
                pos += 1;
                if (pos == _pattern.size())
                {
                    std::cout << "%之后没有对应的格式化字符" << std::endl;
                    return false;
                }
                key = _pattern[pos];
                // 这时候pos指向格式化字符后的位置
                pos += 1;
                if (pos < _pattern.size() && _pattern[pos] == '{')
                {
                    pos += 1; // 这时候pos指向子规则的起始位置
                    while (pos < _pattern.size() && _pattern[pos] != '}')
                    {
                        val.push_back(_pattern[pos++]);
                    }
                    if (pos == _pattern.size())
                    {
                        std::cout << "子规则{}匹配出错" << std::endl;
                        return false;
                    }
                    pos += 1;
                }
                fmt_order.push_back(std::make_pair(key, val));
                key.clear();
                val.clear();
            }
            // 2.根据解析得到的数据初始化格式化子项数组成员
            for (auto &it : fmt_order)
            {
                _items.push_back(createItem(it.first, it.second));
            }
            return true;
        }

    private:
        // 根据不同的格式化字符创建不同的格式化子项对象
        FormatItem::ptr createItem(const std::string &key, const std::string &val)
        {
            if (key == "d")
                return std::make_shared<TimeFormatItem>();
            if (key == "t")
                return std::make_shared<ThreadFormatItem>();
            if (key == "c")
                return std::make_shared<LoggerFormatItem>();
            if (key == "f")
                return std::make_shared<FileFormatItem>();
            if (key == "l")
                return std::make_shared<LineFormatItem>();
            if (key == "p")
                return std::make_shared<LevelFormatItem>();
            if (key == "n")
                return std::make_shared<NLineFormatItem>();
            if (key == "m")
                return std::make_shared<MsgFormatItem>();
            if (key == "T")
                return std::make_shared<TabFormatItem>();
            if(key=="")
                return std::make_shared<OtherFormatItem>(val);
            std::cout<<"没有对应的格式化字符：%"<<key<<std::endl;
            abort();
            return  FormatItem::ptr();
        }

    private:
        std::string _pattern; // 格式化规则字符串 "[%d{%H:%M:%S}] %m%n"
        std::vector<FormatItem::ptr> _items;
    };
}

#endif